Renal vascular resistance using intravascular blood flow and pressure and associated systems, devices, and methods

Abstract

A system includes a processor circuit configured to receive a first set of data. The first set of data includes two pressure measurements and a flow measurement from the vasculature of a patient obtained while the sympathetic nervous system of the patient is not under stimulation. The processor circuit calculates a blood flow resistance value based on the first set of data. The processor circuit then receives a second set of data. The second set of data also includes two pressure measurements and a flow measurement from the vasculature of the patient obtained while the sympathetic nervous system of the patient is stimulated. The processor circuit calculates another blood resistance value based on the second set of data. The processor circuit then compares the two blood flow resistance values to determine whether a denervation procedure would be effective to mitigate the nerve system's response to stimulation. The processor circuit outputs to a screen display metrics obtained from the measurement procedure.

What is claimed is: 
     
         1 . A system comprising:
 a processor circuit configured to:
 receive, from a plurality of sensors, a first set of data associated with blood within a blood vessel of a patient, wherein the plurality of sensors comprises a first pressure sensor, a second pressure sensor, and a flow sensor, wherein the first set of data is obtained without stimulation of a sympathetic nervous system of the patient; 
 determine a first blood flow resistance based on the first set of data; 
 generate a visual representation of the first blood flow resistance; 
 receive, from the plurality of sensors, a second set of data associated with the blood within the blood vessel, wherein the second set of data is obtained with stimulation of the sympathetic nervous system; 
 determine a second blood flow resistance based on the second set of data; 
 generate a visual representation of the second blood flow resistance; and 
 output a screen display to a display in communication with the processor circuit, wherein the screen display comprises the visual representation of the first blood flow resistance and the visual representation of the second blood flow resistance. 
   
     
     
         2 . The system of  claim 1 ,
 wherein the blood vessel comprises a renal artery, and   wherein the nerve comprises a renal nerve.   
     
     
         3 . The system of  claim 1 , wherein the first set of the data and the second set of data are obtained while:
 the first pressure sensor and the flow sensor are positioned within the blood vessel; and   the second pressure sensor is positioned outside of a body of the patient, wherein the second pressure sensor is in direct fluid communication with the blood within the blood vessel.   
     
     
         4 . The system of  claim 1 , wherein the first set of the data and the second set of data are obtained while the first pressure sensor, the second pressure sensor, and the flow sensor are positioned within the blood vessel. 
     
     
         5 . The system of  claim 1 , further comprising a first intravascular catheter or guidewire comprising the first pressure sensor and the flow sensor. 
     
     
         6 . The system of  claim 5 , further comprising a second intravascular catheter or guidewire comprising the second pressure sensor. 
     
     
         7 . The system of  claim 5 ,
 further comprising an intravascular catheter or guidewire,   wherein the intravascular catheter or guidewire comprises the first pressure sensor, the second pressure sensor, and the flow sensor.   
     
     
         8 . The system of  claim 1 , wherein the first set of data and the second set of data each respectively comprise:
 a first pressure measurement obtained by the first pressure sensor;   a second pressure measurement obtained by the second pressure sensor; and   a flow measurement obtained by the flow sensor.   
     
     
         9 . The system of  claim 8 , wherein the first pressure measurement, the second pressure measurement, and the flow measurement are obtained simultaneously. 
     
     
         10 . The system of  claim 1 ,
 wherein the processor circuit is configured to perform a comparison based on the first blood flow resistance and the second blood flow resistance,   wherein the comparison comprises a determination of whether a difference between the first blood flow resistance and the second blood flow resistance exceeds a threshold difference,   wherein the screen display comprises a visual representation based on the determination.   
     
     
         11 . The system of  claim 1 ,
 wherein the processor circuit is configured to perform a comparison based on the first blood flow resistance and the second blood flow resistance,   wherein the comparison comprises a determination of whether denervation is recommended for the patient, and   wherein the screen display comprises a visual representation based on the determination.   
     
     
         12 . The system of  claim 10 ,
 wherein the processor circuit is configured to:
 perform a comparison based on the first blood flow resistance and the second blood flow resistance; and 
 determine a location for a renal denervation procedure based on the comparison, 
   wherein the screen display comprises a visual representation based on the location.   
     
     
         13 . The system of  claim 10 ,
 wherein the processor circuit is configured to:
 perform a comparison based on the first blood flow resistance and the second blood flow resistance; and 
 determine if a renal denervation procedure was successful based on the comparison, and 
   wherein the screen display comprises a visual representation based on the determination of if the renal denervation procedure was successful.   
     
     
         14 . The system of  claim 1 ,
 wherein the first set of data and the second set of data are obtained during a first measurement procedure,   wherein, during a second measurement procedure, the processor circuit is further configured to:
 determine a third blood flow resistance based on a third set of data and a fourth blood flow resistance based on a fourth set of data; and 
 output a further screen display to the display, wherein the further screen display comprises a visual representation of the third blood flow resistance and the fourth blood flow resistance. 
   
     
     
         15 . A method comprising:
 receiving, with a processor circuit, a first set of data associated with blood within a blood vessel of a patient from a plurality of sensors, wherein the plurality of sensors comprises a first pressure sensor, a second pressure sensor, and a flow sensor, wherein the first set of data is obtained without stimulation of a sympathetic nervous system of the patient;   determining, with the processor circuit, a first blood flow resistance based on the first set of data;   generating, with the processor circuit, a visual representation of the first blood flow resistance;   receiving, with the processor circuit, a second set of data associated with the blood within the blood vessel from the plurality of sensors, wherein the second set of data is obtained with stimulation of the sympathetic nervous system;   determining, with the processor circuit, a second blood flow resistance based on the second set of data;   generating, with the processor circuit, a visual representation of the second blood flow resistance; and   outputting, with the processor circuit, a screen display to a display in communication with the processor circuit, wherein the screen display comprises the visual representation of the first blood flow resistance and the visual representation of the second blood flow resistance.   
     
     
         16 . A system comprising:
 an intravascular catheter or guidewire configured to be positioned within a renal artery of a patient, wherein the intravascular catheter or guidewire comprises a first pressure sensor and a flow sensor;   a second pressure sensor; and   a processor circuit configured for communication with the first pressure sensor, the second pressure sensor, and the flow sensor, wherein the processor circuit is configured to:
 receive a first set of data associated with blood within the renal artery and obtained without stimulation of a sympathetic nervous system of the patient; 
 determine a first renal vascular resistance based on the first set of data; 
 generate a visual representation of the first renal vascular resistance; 
 receive a second set of data associated with the blood within the renal artery, 
   wherein the second set of data is obtained with stimulation of the sympathetic nervous system;
 determine a second renal vascular resistance based on the second set of data; 
 generate a visual representation of the second renal vascular resistance; and 
 output a screen display to a display in communication with the processor circuit, 
   wherein the screen display comprises the visual representation of the first renal vascular resistance and the visual representation of the second renal vascular resistance,   wherein the first set of data and the second set of data each respectively comprise:
 a first pressure measurement obtained by the first pressure sensor; 
 a second pressure measurement obtained by the second pressure sensor; and 
 a flow measurement obtained by the flow sensor.